Power system for converting liquid carbon dioxide into mechanical energy based on formic acid hydrogen production

Abstract

The invention provides a power system for converting liquid carbon dioxide into mechanical energy based on formic acid hydrogen production. The power system based on formic acid hydrogen production high-pressure carbon dioxide conversion kinetic energy comprises a formic acid storage tank, the formic acid storage tank is connected with a formic acid pump, and the formic acid pump is connected with a reactor. According to the power system based on formic acid hydrogen production high-pressure carbon dioxide conversion kinetic energy, fuel can be provided for a hydrogen internal combustion engine or a hydrogen fuel cell or a hydrogen gas turbine through formic acid hydrogen production, and meanwhile waste heat generated after combustion or power generation heats hydrogen produced by a hydrogen production reaction kettle and then heats carbon dioxide obtained after refrigeration; the carbon dioxide has high-pressure and high-temperature gas, and the high-pressure and high-temperature carbon dioxide gas provides mechanical power energy for the turbine; liquefied carbon dioxide can be used as a good refrigerant or a fire extinguishing agent, dry ice can also be simply and conveniently prepared, and economic benefits are increased; and the final tail gas carbon dioxide can also be used as a high-quality carbon fertilizer to be supplied to surrounding farmlands.

Description

Technical Field

[0001] This invention relates to the field of formic acid hydrogen production technology, and in particular to a power system based on the conversion of liquid carbon dioxide into mechanical energy during formic acid hydrogen production. Background Technology

[0002] Formic acid (HCOOH) is the simplest monocarboxylic acid containing hydrogen. The Gibbs free energy of the formic acid decomposition reaction to produce hydrogen is negative at room temperature, indicating a thermodynamically favorable reaction. Compared to other hydrogen carriers (such as methanol, methane, synthetic ammonia, and organic hydrogen carriers), which all require high temperature, high pressure, and catalyst-catalyzed reaction conditions, formic acid can decompose into hydrogen and carbon dioxide at room temperature and pressure with only the aid of a catalyst. This minimal energy consumption significantly increases the reaction efficiency; therefore, formic acid-based hydrogen production is currently one of the most economical and feasible methods for hydrogen production.

[0003] However, existing hydrogen storage media such as organic hydrogen carriers, methanol, methane, and synthetic ammonia are all in the gas phase before entering the reactor or reforming chamber during the hydrogen release process. If high-pressure gas is desired, the subsequent compression process requires high energy consumption, which is extremely difficult to achieve. Furthermore, the carbon dioxide and other harmful substances emitted afterward cannot be effectively recovered and reused.

[0004] Formic acid enters the reactor in a liquid state, requiring only minimal energy to reach high pressures, while remaining safe and controllable. During decomposition, the gas naturally accumulates pressure within the reactor to a very high level, a process also requiring minimal energy. This creates conditions for the subsequent low-cost and efficient utilization of carbon dioxide.

[0005] Therefore, it is necessary to provide a new hydrogen production technology based on formic acid, which utilizes the special physicochemical properties of carbon dioxide to solve the above problems through a power system that drives a turbine to output mechanical energy via a low-energy-consumption liquefaction and pressurization process. Summary of the Invention

[0006] The technical problem solved by this invention is to provide a hydrogen production technology using formic acid, which can simultaneously provide fuel for a hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine, and recover and reuse the waste heat from the exhaust gas emitted by the hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine to heat the formic acid hydrogen production reactor; the gaseous carbon dioxide, after being cooled by reheating liquid carbon dioxide, reaches a high temperature and high pressure, and the high temperature and high pressure carbon dioxide serves as the power system for the turbine to output mechanical energy.

[0007] To solve the above-mentioned technical problems, the present invention provides a power system based on the high-pressure carbon dioxide conversion kinetic energy of formic acid to hydrogen production, comprising: a formic acid storage tank, the formic acid storage tank being connected to a formic acid pump, the formic acid pump being connected to a reactor, the formic acid pump being used to stably inject formic acid from the formic acid storage tank into the reactor under pressure, the reactor being connected to a carbon dioxide separator, the carbon dioxide separator being connected to a carbon dioxide storage tank, the carbon dioxide separator being connected to a hydrogen storage tank, the hydrogen storage tank being connected to a hydrogen internal combustion engine or a hydrogen fuel cell or a hydrogen gas turbine, the hydrogen internal combustion engine or hydrogen fuel cell or hydrogen gas turbine being connected to a powertrain; the carbon dioxide storage tank being connected to a heat exchanger, the heat exchanger being connected to a waste heat heater, the waste heat heater being connected to a turbine, and the turbine being connected to the powertrain.

[0008] Preferably, the reactor is connected to a primary condenser, the primary condenser is connected to a secondary condenser, and the secondary condenser is connected to the carbon dioxide separator.

[0009] Preferably, the hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine is connected to the reactor and the waste heat heater, and the exhaust waste heat generated by the hydrogen internal combustion engine during operation is used as a heat source for the reactor and for heating gaseous carbon dioxide through the waste heat heater.

[0010] Preferably, the formic acid in the formic acid storage tank is added to the reactor via a formic acid pump. In the reactor, the formic acid is decomposed into a mixture of hydrogen and carbon dioxide gases by a catalyst. After being pressurized to the required pressure, the mixture is separated by a temperature-controlled gas-liquid separator. Heat exchange is performed through the primary and secondary condensers. The temperature of the mixed gas exiting the primary condenser is greater than 35°C, and the temperature of the mixed gas exiting the secondary condenser is -70°C to 30°C.

[0011] Preferably, the reactor decomposes formic acid into a mixture of hydrogen and carbon dioxide under the action of a catalyst. At this time, the valve of the reactor is closed. As the reaction continues, the mixed gas is continuously generated and gradually pressurized in the reactor to 0.1-100 MPa. After reaching the set pressure, the high-pressure mixed gas is stably released through the electromagnetic valve to balance the gas produced by the reaction with the released gas. Then, heat exchange is carried out through the primary condenser and the secondary condenser.

[0012] Preferably, the heat exchanger is used to vaporize and gradually release the liquid carbon dioxide in the carbon dioxide storage tank and use the vaporized liquid carbon dioxide as a refrigerant.

[0013] Preferably, the waste heat heater is used to heat the vaporized carbon dioxide to generate a high-pressure carbon dioxide gas flow, which is used to drive the turbine to do work.

[0014] Preferably, the high-pressure carbon dioxide can be used as a raw material to manufacture one or more of the following: dry ice, mobile fire extinguishing agents, refrigerants, extraction solvents, cold chain food and medicine preservatives, crop carbon fertilizers, and marine plant and animal carbon sources.

[0015] Preferably, the reactor is made of one or a combination of several of the following materials: 2507 special super duplex steel, titanium, zirconium, aluminum, or special plastic inner liner wrapped with carbon fiber material.

[0016] Preferably, the 2507 special super duplex steel includes models such as UNSS32750, DIN / EN1.4410, and ASTMA240.

[0017] Preferably, the formic acid storage tank is made of acid-resistant metal or plastic.

[0018] Preferably, the formic acid storage tank is made of one or a combination of titanium, zirconium, polycarbonate, polytetrafluoroethylene, polypropylene, and polyethylene.

[0019] Compared with related technologies, the power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production provided by this invention has the following beneficial effects:

[0020] This invention provides a power system based on the high-pressure carbon dioxide conversion kinetic energy of formic acid to hydrogen production. Leveraging the characteristics of formic acid to hydrogen production, formic acid decomposes into hydrogen and CO2 under low energy consumption. The hydrogen and CO2 are naturally pressurized to 0.1–100 MPa in a reactor, and then separated through heat exchange and cooling. The hydrogen is used as fuel for a hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine. The waste heat generated satisfies the heat required for the formic acid to hydrogen production reaction in the reactor, and the remaining heat satisfies the heat required for the reheat expansion of carbon dioxide. Most of the heat is reused, greatly increasing the efficiency of the hydrogen internal combustion engine. The thermal efficiency of hydrogen fuel cells or hydrogen gas turbines can be improved while reducing energy consumption; liquid carbon dioxide absorbs a large amount of heat during vaporization, making it an excellent refrigerant to meet the cooling requirements of cold chain transportation; low-temperature gaseous CO2 expands rapidly after being heated by waste heat, generating a high-temperature, high-pressure CO2 gas stream. Since CO2 has a higher specific gravity than water vapor and air, the work done by the same high-pressure CO2 is greater than that done by water vapor or hot air; the high-temperature, high-pressure CO2 gas stream serves as a good power source, driving a turbine to do work, and the work done should be 10 to 20 times the energy produced by the combustion of H2.

[0021] This can increase the overall thermal efficiency of hydrogen internal combustion engines to over 80%, while also effectively improving the utilization efficiency of hydrogen fuel cells and reducing the thermal emissions of hydrogen gas turbines in specific application scenarios. The overall driving range can exceed that of hydrogen internal combustion engines by 10 to 20 times, while also generating a good cooling source, which can effectively reduce operating costs in special application scenarios, particularly in refrigerated trucks and fishing vessels for cold chain preservation. Attached Figure Description

[0022] Figure 1 A schematic diagram of the power system based on the high-pressure carbon dioxide conversion kinetic energy for hydrogen production from formic acid, provided by the present invention;

[0023] Figure 2 The structural diagram of the power system based on high-pressure carbon dioxide conversion for hydrogen production from formic acid, provided by the present invention, applied to the rear of a cold chain vehicle;

[0024] Figure 3 The structural diagram of the power system based on high-pressure carbon dioxide conversion for hydrogen production from formic acid, provided by the present invention, applied to an ocean fishing vessel;

[0025] Figure 4 The structural diagram of the power system based on high-pressure carbon dioxide conversion for hydrogen production provided by the present invention after being applied to a hydrogen refueling and charging station;

[0026] Figure 5 The diagram shows the structure of the power system based on formic acid hydrogen production and high-pressure carbon dioxide conversion kinetic energy provided by this invention, applied to a stealth aircraft.

[0027] The following are the labels in the diagram: 1. Primary condenser, 2. Secondary condenser, 3. Carbon dioxide separator, 4. Hydrogen internal combustion engine or hydrogen fuel cell or hydrogen gas turbine, 5. Heat exchanger, 6. Formic acid storage tank, 7. Reactor, 8. Carbon dioxide storage tank, 9. Waste heat heater, 10. Turbine, 11. Powertrain, 12. Formic acid pump, 13. Hydrogen storage tank. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Please refer to the following: Figure 1 ,in, Figure 1 This invention provides a schematic diagram of a power system for hydrogen production from formic acid using high-pressure carbon dioxide conversion. The power system includes: a formic acid storage tank 6, connected to a formic acid pump 12, which is connected to a reactor 7. The formic acid pump 12 is used to stably inject formic acid from the formic acid storage tank 6 into the reactor 7 under pressure. The reactor 7 is connected to a carbon dioxide separator 3, which is connected to a carbon dioxide storage tank 8. The carbon dioxide separator 3 is connected to a hydrogen storage tank 13, which is connected to a hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine 4. The hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine 4 is connected to a powertrain 11. The carbon dioxide storage tank 8 is connected to a heat exchanger 5, which is connected to a waste heat heater 9. The waste heat heater 9 is connected to a turbine 10, which is connected to the powertrain 11.

[0030] The reactor 7 is connected to a primary condenser 1, the primary condenser 1 is connected to a secondary condenser 2, the secondary condenser 2 is connected to the carbon dioxide separator 3, and the primary condenser 1, the secondary condenser 2 and the carbon dioxide separator 3 can be installed as a single unit.

[0031] The hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine 4 is connected to the reactor 7 and the waste heat heater 9. The waste heat generated by the exhaust gas when the hydrogen internal combustion engine 4 is working is used as a heat source for the reactor 7 and for heating gaseous carbon dioxide through the waste heat heater 9.

[0032] The formic acid in the formic acid storage tank 6 is added to the reactor 7 via the formic acid pump 12. In the reactor 7, the formic acid is decomposed into a mixed gas of hydrogen and carbon dioxide by the action of a catalyst. After being pressurized to the required pressure, the gas is separated by a temperature-controlled gas-liquid separator. The mixture is then exchanged for heat through the primary condenser 1 and the secondary condenser 2. The temperature of the mixed gas exiting the primary condenser 1 is greater than 35°C, and the temperature of the mixed gas exiting the secondary condenser 2 is -70°C to 30°C.

[0033] The reactor 7 decomposes formic acid into a mixture of hydrogen and carbon dioxide under the action of a catalyst. At this time, the valve of the reactor 7 is closed. As the reaction continues, the mixed gas is continuously generated and gradually pressurized in the reactor to 0.1-100 MPa. After reaching the set pressure, the high-pressure mixed gas is stably released through the electromagnetic valve to balance the gas produced by the reaction with the released gas. Then, heat exchange is carried out through the first-stage condenser 1 and the second-stage condenser 2.

[0034] The heat exchanger 5 is used to vaporize and gradually release the liquid carbon dioxide in the carbon dioxide storage tank 8 and use the vaporized liquid carbon dioxide as a refrigerant.

[0035] The waste heat heater 9 is used to heat the vaporized carbon dioxide to generate a high-pressure carbon dioxide gas flow, which is used to drive the turbine 10 to do work.

[0036] The high-pressure carbon dioxide can be used as a raw material to manufacture: dry ice, mobile fire extinguishing agents, refrigerants, extraction solvents, cold chain food and medicine preservatives, crop carbon fertilizers, and marine animal and plant carbon sources, or a combination of several of these.

[0037] The reactor 7 is made of one or more of the following materials: 2507 special super duplex steel, titanium, zirconium, aluminum, or special plastic inner liner wrapped with carbon fiber material.

[0038] The 2507 special super duplex steel includes models such as UNSS32750, DIN / EN 1.4410, and ASTMA240.

[0039] The formic acid storage tank 6 is made of acid-resistant metal or plastic.

[0040] The formic acid storage tank 6 is made of one or a combination of titanium, zirconium, polycarbonate, polytetrafluoroethylene, polypropylene, and polyethylene.

[0041] Normal air compressors require a large amount of energy to compress air. This invention utilizes the special property of formic acid to produce hydrogen (for details, please refer to the lightweight acid-resistant and high-pressure resistant formic acid hydrogen production reactor and purification system integrated device disclosed in application number CN202211635590.6) to change the liquid state to the gaseous state. By using a catalyst to catalyze formic acid, a large amount of H2 and CO2 are continuously generated, and the product pressure can be stored up to 0.1 to 100 MPa without additional energy consumption.

[0042] HCOOH (liquid) ---- H2 (gaseous) + CO2 (gaseous)

[0043] When the mixed gas pressure reaches 15 MPa, the partial pressure of CO2 reaches 7 MPa. When the temperature drops below 30°C (in a low-power air-cooled system), the CO2 becomes liquid. Utilizing the strong endothermic property of liquid CO2 vaporization (578 KJ / kg), the collected liquid CO2 is transformed into a high-quality, pollution-free cold source, replacing the highly polluting and energy-intensive Freon refrigerant. Modern refrigerated trucks have widely adopted dry ice refrigeration to replace electricity, increasing driving range while effectively isolating oxygen for better preservation.

[0044] CO2 (liquid) ---- CO2 (gas) - 587 kJ / kg

[0045] This has significant advantages in cold chain transportation and preservation, while also saving a large amount of electricity and being more environmentally friendly.

[0046] Simultaneously, liquid CO2 expands rapidly after absorbing heat, increasing its pressure and generating a large amount of energy that can be recovered and reused. Previously, an effective method of utilization was the creation of rock-fracturing pipes using liquid CO2.

[0047] This invention uses a two-stage waste heat recovery system to heat CO2. The waste heat generated after the combustion of hydrogen internal combustion engine or hydrogen gas turbine (or after the fuel cell generates electricity) is used to supplement the reactor 7 and then reused to heat CO2. This generates pressure steadily with extremely low energy consumption, and the pressure can be restored up to 15 MPa. The high pressure drives the turbine impeller to do work and generate mechanical energy.

[0048] CO2 has a molecular weight of 44, far exceeding that of air (29), and produces significantly more energy than high-pressure steam (molecular weight 18). High-temperature, high-pressure CO2 is 20-30% more efficient at performing work than air or steam. However, conventional methods for utilizing CO2 require substantial energy consumption in the compression and liquefaction stages, and the subsequent expansion and work generated by reheating CO2 also necessitates additional energy, making it difficult to achieve an economic balance. This invention, however, utilizes extremely low energy consumption to complete this process, representing a milestone in CO2 utilization.

[0049] This invention utilizes the hydrogen production properties of formic acid, significantly reducing energy consumption and increasing the multi-stage utilization of CO2. It has extremely high application value in hydrogen energy, power, and refrigeration, and is particularly suitable for special applications such as refrigerated trucks. It can even be equipped with a fire extinguishing function.

[0050] This invention, as a power system, allows for customization of the reactor 7 size to suit different application scenarios, such as vehicle power, marine power, and small hydrogen-powered vehicles. The layout can be customized to meet specific needs.

[0051] In particular, fishing boats need to load large amounts of ice before each departure to preserve their catch. Using this system, the carbon dioxide refrigeration produced can fully meet the needs of seafood preservation, saving significant resources while improving the taste of the catch and increasing its economic value. The generated CO2 can be released into seawater, completely dissolving and increasing the growth source for marine life and plant photosynthesis, effectively solving the challenges of the entire carbon dioxide CCUS industrial chain. This industrial chain is more energy-efficient, more environmentally friendly, and safer.

[0052] This invention aims to transform formic acid from a general chemical raw material into an energy source, promoting the development of formic acid hydrogen energy storage, transportation, production, and CCUS in a more convenient, faster, more economical, and safer manner, and facilitating the transformation of gas stations into formic acid refueling stations. It also enables the conversion of ships, automobiles, and airplanes from petroleum-based energy sources to formic acid-based energy sources.

[0053] Formic acid can be produced from waste CO2 through green wind and solar power at extremely low cost. Alternatively, it can be produced from the waste heat of high-temperature slag from steel plants by recycling and reusing it to reduce CO2 and produce high-energy-consuming, high-temperature, and high-content carbon monoxide.

[0054] The process involves recycling and reusing waste energy, reducing CO2 to produce formic acid (a high-energy fuel), a chemical product with high added value. The formic acid is then transported to places that need energy at extremely low transportation costs, where hydrogen is produced on-site or formic acid is directly added, and then CO2 is efficiently utilized, thus realizing a closed loop for the entire industry.

[0055] The working principle of the power system for converting liquid carbon dioxide into mechanical energy based on formic acid hydrogen production provided by this invention is as follows:

[0056] Formic acid in formic acid storage tank 6 is pumped into titanium reactor 7. Using the formic acid hydrogen production technology patented by Beijing Huapu Technology Co., Ltd., hydrogen and CO2 are generated in titanium reactor 7. The hydrogen and CO2 are naturally pressurized to 0.1-100MPa. The temperature and pressure systems are kept stable by DCS or PLC automatic control system. After heat exchange in primary condenser 1 to above 35℃ and secondary condenser to -70 to 30℃, CO2 is liquefied in carbon dioxide separator 3 and flows into carbon dioxide storage tank 8.

[0057] The separated hydrogen has a purity of over 99% and enters the hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine 4 to perform work on the powertrain 11 to provide power. Part of the waste heat from the exhaust gas generated by the hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine 4 is returned to the titanium reactor 7 as a heat source, and part of it is provided to the waste heat heater 9 to heat the low-temperature CO2.

[0058] Liquid CO2 is cooled and absorbs a large amount of heat in heat exchanger 5, and then vaporizes. The vaporized low-temperature CO2 is heated by waste heat heater 9, which is provided by waste heat from hydrogen internal combustion engine, hydrogen fuel cell or hydrogen gas turbine 4. The volume expands and the pressure increases. The high-pressure CO2 expands and generates a large amount of mechanical energy (about 10 to 20 times the heat energy of H2 combustion), which drives turbine 10 to do work and inputs it into power assembly 11.

[0059] Compared with related technologies, the power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production provided by this invention has the following beneficial effects:

[0060] This invention provides a power system based on the conversion of liquid carbon dioxide into mechanical energy through formic acid hydrogen production. Utilizing the characteristics of formic acid hydrogen production, hydrogen and CO2 are produced without consuming additional energy. The system is naturally pressurized to over 15 MPa, separating liquid CO2 and hydrogen. The hydrogen serves as fuel for a hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine. The heat generated satisfies the heat required for the formic acid decomposition reaction in the reactor, achieving heat balance and significantly increasing the efficiency of the hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine while saving energy. The liquid carbon dioxide absorbs a large amount of heat during vaporization, making it an excellent refrigerant to meet the cooling requirements of refrigerated transport vehicles. After being heated by waste heat, the low-temperature CO2 rapidly expands in volume, generating a high-pressure gas flow. Since CO2 has a higher specific gravity than water vapor and air, the work done by the high-pressure CO2 is also greater than that done by water vapor and air. This high-pressure CO2 gas flow serves as a good power source, driving a turbine to perform work that is 10 to 20 times the energy produced by the combustion of H2, making it a suitable power source.

[0061] This can increase the overall efficiency of hydrogen internal combustion engines, hydrogen fuel cells, or hydrogen gas turbines to over 80%, and increase the driving range to 10 to 20 times the original. At the same time, it generates a good cooling source. Using this technology will greatly reduce energy consumption, improve economic efficiency, and enhance safety.

[0062] Example 1:

[0063] Please refer to the following: Figure 2 , Figure 2 The structural diagram of the power system based on formic acid hydrogen production and the conversion of liquid carbon dioxide into mechanical energy, provided by this invention, is applied to the rear of a cold chain vehicle:

[0064] In this embodiment, when the refrigerated truck starts, a small amount of hydrogen stored in the hydrogen storage tank 13 is used as starting energy and enters the hydrogen internal combustion engine, hydrogen gas turbine, or hydrogen fuel cell 4; or the stored high-pressure carbon dioxide turbine 10 generates electricity (or a storage battery) to supply power to the reactor 7 to heat the reaction, so that the system reaches and is in the normal start-up stage (the system may not be equipped with a hydrogen storage tank).

[0065] Meanwhile, when the car starts, the electric heater in reactor 7 begins to preheat. When the hydrogen internal combustion engine, hydrogen gas turbine, or hydrogen fuel cell 4 starts working, the residual heat enters the heating layer of reactor 7, taking over the electric heater to provide heat to reactor 7.

[0066] The small amount of hydrogen stored in hydrogen storage tank 13 is only sufficient to preheat and start up reactor 7 (the system may not need to be equipped with a hydrogen storage tank).

[0067] When the temperature in reactor 7 reaches the preheating temperature or the liquid level falls below the set level, formic acid is quantitatively added to reactor 7 from formic acid storage tank 6 via formic acid pump 12, initiating the generation of large quantities of hydrogen and carbon dioxide. After cooling and separation, the hydrogen is continuously added to the hydrogen internal combustion engine and hydrogen gas turbine via hydrogen storage tank 13, achieving continuous circulation. The carbon dioxide is separated into liquid phase and stored in liquid carbon dioxide storage tank 8.

[0068] When the cab requires air conditioning, the valve opens, allowing a small amount of liquid carbon dioxide to enter the cab's air conditioning heat exchanger for cooling. The valve closes when the air conditioning is turned off.

[0069] When the refrigeration of the cold chain cabinet is turned on, the valve of the liquid carbon dioxide storage tank 8 is opened, and heat is exchanged through the refrigeration heat exchanger (refrigeration evaporator) in the cold chain cabinet, thereby reducing the temperature in the cold chain cabinet.

[0070] After heat exchange, the carbon dioxide enters the waste heat heater 9 for heating after multiple heat exchange stages. It then drives the turbine 10 to transmit mechanical energy to the powertrain 11. After being cooled by the heat exchanger, part of it enters the cold chain cabinet to remove oxygen from the cabinet and play a role in preservation, while the rest is emitted as exhaust gas.

[0071] When the refrigerated truck is shut down, the high-temperature exhaust gas is directly discharged without entering the heating layer of reactor 7. The residual heat of reactor 7 and the formic acid pump 12 are shut down. The hydrogen generated from the residual heat and the remaining formic acid is stored in hydrogen storage tank 13 for use in the next startup. The generated carbon dioxide is liquefied and stored in liquid phase carbon dioxide storage tank 8 as a supplement to the cold source.

[0072] Example 2:

[0073] Please refer to the following: Figure 3 , Figure 3 The structural diagram of the power system based on formic acid hydrogen production and the conversion of liquid carbon dioxide into mechanical energy, as provided by this invention, is shown below when applied to an ocean fishing vessel:

[0074] In this embodiment, when the fishing boat starts, the hydrogen stored in the hydrogen storage tank 13 serves as the starting energy, entering the hydrogen internal combustion engine, hydrogen gas turbine, or hydrogen fuel cell 4 to begin combustion or power generation. The output mechanical energy drives the propeller to rotate at high speed through the powertrain 11, propelling the fishing boat forward.

[0075] Meanwhile, when the fishing boat starts, the electric heater in reactor 7 begins to preheat. When the hydrogen internal combustion engine, hydrogen gas turbine, or hydrogen fuel cell 4 starts working, the residual heat enters the heating layer of reactor 7, taking over the heat supply to reactor 7 from the electric heater.

[0076] The hydrogen stored in hydrogen storage tank 13 is only sufficient to preheat and start up reactor 7.

[0077] When the temperature in reactor 7 reaches the preheating temperature or the liquid level falls below the set level, formic acid is quantitatively added to reactor 7 from formic acid storage tank 6 via formic acid pump 12, initiating the generation of large quantities of hydrogen and carbon dioxide. After cooling and separation, the hydrogen is continuously added to the hydrogen internal combustion engine and hydrogen gas turbine via hydrogen storage tank 13, achieving continuous circulation. The carbon dioxide is separated into liquid phase and stored in liquid carbon dioxide storage tank 8.

[0078] The liquid carbon dioxide produced in the early stages of fishing at sea can be sprayed out by valves to make dry ice, which can be stored in the cargo hold as an emergency cold source for preservation or brought back to shore for sale.

[0079] When the catch needs to be kept fresh, the valve of the liquid carbon dioxide storage tank 8 is opened when the refrigeration is turned on. The carbon dioxide passes through the heat exchanger in the fish hold, which exchanges heat and lowers the temperature in the fish hold. The fish hold is kept under a slight positive pressure, which prevents oxygen from entering the fish hold and thus keeps the fish fresh.

[0080] After heat exchange, the carbon dioxide enters the waste heat heater 9 for heating after multiple heat exchange stages. Then, it blows the turbine 10 to transmit mechanical energy to the powertrain 11. After being cooled by the heat exchanger 5, part of it enters the fish tank, squeezing out the oxygen in the fish tank, and part of it is directly introduced into the seawater as exhaust gas. The volume ratio of dissolved carbon dioxide in seawater can reach 1:1, so there is no carbon emission in the whole process.

[0081] When the fishing boat's engine is shut down, the high-temperature exhaust gas is directly discharged without entering the heating layer of reactor 7. The residual heat of reactor 7 and the formic acid pump 12 are shut down. The hydrogen generated from the residual heat and the remaining formic acid is stored in hydrogen storage tank 13 for use in the next startup. The carbon dioxide generated is liquefied and stored in liquid phase carbon dioxide storage tank 8 as a supplement to the cold source or made into dry ice for transport back.

[0082] Example 3:

[0083] Please refer to the following: Figure 4 , Figure 4 The structural diagram of the power system based on formic acid hydrogen production and the conversion of liquid carbon dioxide into mechanical energy provided by this invention after being applied to a hydrogen refueling and charging station is as follows:

[0084] In this embodiment, when the hydrogen refueling station system is started, the hydrogen stored in the hydrogen storage tank 13 is used as the starting energy, and a small amount of hydrogen is separated and enters the hydrogen internal combustion engine, hydrogen gas turbine, or hydrogen fuel cell 4 to start combustion or power generation.

[0085] Meanwhile, when the system starts up, the electric heater in reactor 7 begins to preheat. When the hydrogen internal combustion engine, hydrogen gas turbine, or hydrogen fuel cell 4 starts working, the residual heat enters the heating layer of reactor 7, taking over the electric heater to provide heat to reactor 7.

[0086] This hydrogen storage tank 13 is a high-pressure hydrogen storage tank, connected to a hydrogen refueling system, which can meet the refueling needs of general hydrogen-powered electric vehicles, sightseeing vehicles, and even hydrogen-powered cars.

[0087] When the temperature in reactor 7 reaches the preheating temperature or the liquid level falls below the set level, formic acid is quantitatively added to reactor 7 from formic acid storage tank 6 via formic acid pump 12, initiating the generation of large quantities of hydrogen and carbon dioxide. After cooling and separation, the hydrogen is continuously added to the hydrogen internal combustion engine and hydrogen gas turbine via hydrogen storage tank 13, achieving continuous circulation. The carbon dioxide is separated into liquid phase and stored in liquid carbon dioxide storage tank 8.

[0088] When the cooling system is turned on, valve 8 of the liquid carbon dioxide storage tank opens, and heat is exchanged through the air conditioner's refrigeration heat exchanger. In summer, it can be used as a cold source for air conditioning.

[0089] After heat exchange, the carbon dioxide undergoes multiple heat exchange stages before entering the waste heat heater 9 for further heating. It then drives the turbine 10 to transmit mechanical energy to the power assembly 11. After being cooled by the heat exchanger 5, it is stored in a carbon dioxide gas holder and piped to greenhouses or open fields for use as a good carbon fertilizer.

[0090] If there is no farmland or greenhouses nearby, most of the liquid carbon dioxide can be separated and made into dry ice using a dry ice machine. This dry ice can then be sold as an economic product. This process consumes no energy and is highly profitable, making it another source of income for hydrogen refueling stations.

[0091] When the system uses a fuel cell system, it can be used directly as a power supply system. When the system uses a hydrogen internal combustion engine system, hydrogen enters the hydrogen internal combustion engine and converts into mechanical energy to drive the generator. At the same time, high-temperature and high-pressure carbon dioxide passes through turbine 10 to generate mechanical energy to drive the generator to produce electricity. The entire power supply system is connected to an electric vehicle charging station to charge electric vehicles. It can also be used directly as a backup power source or a main power source to supplement the power supply of hydrogen refueling stations.

[0092] When the system is shut down, the high-temperature exhaust gas is directly discharged without entering the heating layer of reactor 7. The residual heat of reactor 7 and the formic acid pump are shut down. The hydrogen generated from the residual heat and the remaining formic acid is stored in a hydrogen storage tank for use in the next startup. The generated carbon dioxide is liquefied and stored in a liquid carbon dioxide storage tank as a supplement to the cold source.

[0093] Example 4:

[0094] Please refer to the following: Figure 5 , Figure 5 The structural diagram of the power system based on formic acid hydrogen production and the conversion of liquid carbon dioxide into mechanical energy, provided by this invention, is shown below when applied to a stealth-enabled aircraft:

[0095] The exhaust plume of aircraft engines, being the largest heat source detectable by infrared sensors, has long lacked a viable solution. This invention provides a solution that utilizes immense power while making the exhaust plume temperature difficult to detect.

[0096] In this embodiment, when the aircraft starts, the hydrogen stored in the hydrogen storage tank 13 serves as the starting energy source, entering the hydrogen gas turbine and beginning combustion. Simultaneously, the stored liquid carbon dioxide, after heat exchange, enters the turbine 10 to provide takeoff power.

[0097] The stored hydrogen is a safe reserve, meaning that the reactor can still be safely returned to port in the event of a malfunction in reactor 7.

[0098] Meanwhile, when the aircraft starts, the electric heater in reactor 7 begins to preheat. When the hydrogen internal combustion engine starts working, the residual heat enters the heating layer of reactor 7, taking over the heat supply to reactor 7 from the electric heater.

[0099] When the temperature in reactor 7 reaches the preheating temperature or the liquid level falls below the set level, formic acid is metered and injected into reactor 7 from the formic acid storage tank via a formic acid pump, initiating the generation of large quantities of hydrogen and carbon dioxide. After cooling and separation, the hydrogen is continuously fed into the hydrogen internal combustion engine and hydrogen gas turbine via hydrogen storage tank 13, achieving continuous circulation. The carbon dioxide is separated into liquid phase and stored in liquid carbon dioxide storage tank 8.

[0100] The stored liquid carbon dioxide can be used to cool and heat the aircraft exhaust, reducing the final exhaust temperature to below 200°C. Any remaining carbon dioxide can be used for emergency firefighting, and even as a rainmaking agent in special circumstances.

[0101] After heat exchange, the carbon dioxide enters the waste heat heater 9 for heating after multiple heat exchange stages, and then blows the turbine 10 to transmit mechanical energy to the power assembly 11.

[0102] When the aircraft engine is shut down, the high-temperature exhaust gas is directly discharged without entering the heating layer of reactor 7. The residual heat of reactor 7 and the formic acid pump 12 are shut down. The hydrogen generated from the residual heat and the remaining formic acid is stored in hydrogen storage tank 13 for use in the next startup. The generated carbon dioxide is liquefied and stored in liquid phase carbon dioxide storage tank 8 as a supplement to the acceleration turbine.

[0103] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A power system for converting liquid carbon dioxide into mechanical energy based on hydrogen production from formic acid, characterized by, include: A formic acid storage tank is provided, connected to a formic acid pump, which is connected to a reactor. The formic acid pump is used to stably inject formic acid from the formic acid storage tank into the reactor under pressure. The reactor is connected to a carbon dioxide separator, which is connected to a carbon dioxide storage tank. The carbon dioxide separator is connected to a hydrogen storage tank, which is connected to a hydrogen internal combustion engine, a hydrogen fuel cell, or a hydrogen gas turbine. The hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine is connected to a powertrain. The carbon dioxide storage tank is connected to a heat exchanger, which is connected to a waste heat heater. The waste heat heater is connected to a turbine, which is connected to the powertrain.

2. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 1, characterized in that, The reactor is connected to a primary condenser, which is connected to a secondary condenser, which is connected to the carbon dioxide separator.

3. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 1, characterized in that, The hydrogen internal combustion engine, hydrogen fuel cell, or hydrogen gas turbine is connected to the reactor and the waste heat heater. The waste heat generated by the exhaust gas when the hydrogen internal combustion engine is working is used as a heat source for the reactor and for heating gaseous carbon dioxide through the waste heat heater.

4. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 1, characterized in that, Formic acid in the formic acid storage tank is added to the reactor via a formic acid pump. In the reactor, formic acid is decomposed into a mixture of hydrogen and carbon dioxide gases by a catalyst. After being pressurized to the required pressure, the mixture is separated by a temperature-controlled gas-liquid separator. Heat exchange occurs through the primary and secondary condensers. The temperature of the mixed gas exiting the primary condenser is greater than 35°C, and the temperature of the mixed gas exiting the secondary condenser is -70°C to 30°C.

5. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 4, characterized in that, The reactor decomposes formic acid into a mixture of hydrogen and carbon dioxide under the action of a catalyst. At this time, the valve of the reactor is closed. As the reaction continues, the mixed gas is continuously generated and gradually pressurized in the reactor to 0.1-100 MPa. After reaching the set pressure, the high-pressure mixed gas is stably released through the electromagnetic valve to balance the gas produced by the reaction with the released gas. Then, heat exchange is carried out through the first-stage condenser and the second-stage condenser.

6. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 3, characterized in that, The heat exchanger is used to vaporize and gradually release the liquid carbon dioxide in the carbon dioxide storage tank and use the vaporized liquid carbon dioxide as a refrigerant.

7. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 6, characterized in that, The waste heat heater is used to heat the vaporized carbon dioxide to generate a high-pressure carbon dioxide gas flow, which is used to drive the turbine to do work.

8. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 7, characterized in that, The high-pressure carbon dioxide can be used as a raw material to manufacture: dry ice, mobile fire extinguishing agents, refrigerants, extraction solvents, cold chain food and medicine preservatives, crop carbon fertilizers, and marine animal and plant carbon sources, or a combination of several of these.

9. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 1, characterized in that, The reactor is made of one or a combination of several of the following materials: 2507 special super duplex steel, titanium, zirconium, aluminum, or special plastic inner liner wrapped with carbon fiber material.

10. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 9, characterized in that, The 2507 special super duplex steel includes models such as UNS S32750, DIN / EN1.4410, and ASTMA240.

11. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 1, characterized in that, The formic acid storage tank is made of acid-resistant metal or plastic.

12. The power system based on the high-pressure carbon dioxide conversion kinetic energy for formic acid hydrogen production according to claim 11, characterized in that, The formic acid storage tank is made of one or a combination of titanium, zirconium, polycarbonate, polytetrafluoroethylene, polypropylene, and polyethylene.

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